标题： 光激发超晶格中的波前、脉冲和波列在作为可激发或振荡介质时的表现 显示英文标题

标题： Wave fronts, pulses and wave trains in photoexcited superlattices behaving as excitable or oscillatory media

摘要： 未掺杂且强光激发的具有场依赖复合的半导体超晶格表现出可激发或振荡介质的特性，具有空间离散的非线性对流和扩散。 无限长的直流电流偏置超晶格作为可激发介质时，会表现出具有增加或减少轮廓的波前，其速度可以通过渐近方法计算。 这些超晶格还可以支持电场脉冲。 沿电子通量下游移动的脉冲可以从其组成部分的波前来构建，而沿上游移动的脉冲则移动缓慢并经历跳跃运动：它们在长时间间隔内缓慢变化，而在快速过渡期间，脉冲跳转到之前的超晶格周期。 光激发的超晶格也可以作为振荡介质并表现出波列。 显示英文摘要

摘要： Undoped and strongly photoexcited semiconductor superlattices with field-dependent recombination behave as excitable or oscillatory media with spatially discrete nonlinear convection and diffusion. Infinitely long, dc-current-biased superlattices behaving as excitable media exhibit wave fronts with increasing or decreasing profiles, whose velocities can be calculated by means of asymptotic methods. These superlattices can also support pulses of the electric field. Pulses moving downstream with the flux of electrons can be constructed from their component wave fronts, whereas pulses advancing upstream do so slowly and experience saltatory motion: they change slowly in long intervals of time separated by fast transitions during which the pulses jump to the previous superlattice period. Photoexcited superlattices can also behave as oscillatory media and exhibit wave trains.